from __future__ import print_function
# author:zhangshuyx@gmail.com

#!/usr/bin/env python
# -*- coding=utf-8 -*-

import os

# define the result filename
resultfile = 'result.csv'

# the merge func
def merge():
    """merge csv files to one file"""

    # indicates use of a global variable.
    global resultfile

    # use list save the csv files
    csvfiles = [f for f in os.listdir('.') if f != resultfile  \
    and (len(f.split('.')) >= 2) and f.split('.')[1]=='csv']

    # open file to write
    with open(resultfile,'w') as writefile:
        for csvfile in csvfiles:
            with open(csvfile) as readfile:
                print('File {} readed.'.format(csvfile))
                
                # do the read and write
                writefile.write(readfile.read()+'\n')
    print('\nFile {} wrote.'.format(resultfile))

# the main program

def main():
    print("\t\tMerge\n\n")
    print("This program merges csv-files to one file\n")
    merge()

if __name__ == '__main__':
    main()
